Place pieces of gingerbread into a food processor and pulse until fine. Reserve a couple of tablespoonfuls of crumbs for decorating.
Place the dark chocolate, butter and cream in a microwave safe bowl and heat on high for 1 minute. Give the mixture a good stir until smooth (you may need to microwave it for another 10 seconds).
Once smooth, add the gingerbread crumbs (reserving a little for decoration), then stir through the Creme de Cacao. Chill mixture for 15 minutes to make it thick enough to roll into balls.
Once chilled, roll a small tablespoon of mixture into a ball ( I use a small sized ice cream scoop) and place onto a lined tray. Continue with the rest of the mixture, then chill again for 15 minutes.
In a small microwave bowl (not glass) heat around 270g of the milk chocolate in the microwave for 1 minute. Stir well, then microwave for another 10-20 seconds. Give the chocolate a good stir. If it has all melted, add the rest of the chocolate and stir vigorously, to temper.
Remove the balls from the fridge and dip in the melted chocolate. Lift out with a fork and tap to remove excess. Place on another lined tray, then sprinkle with reserved gingerbread crumbs.
Stored in the fridge, the truffles should last a couple of weeks.